mirror of
https://github.com/php/php-src.git
synced 2024-09-23 02:47:26 +00:00
134 lines
3.0 KiB
PHP
Executable File
134 lines
3.0 KiB
PHP
Executable File
<?php
|
|
|
|
/** @file limititerator.inc
|
|
* @ingroup SPL
|
|
* @brief class LimitIterator
|
|
* @author Marcus Boerger
|
|
* @date 2003 - 2009
|
|
*
|
|
* SPL - Standard PHP Library
|
|
*/
|
|
|
|
/**
|
|
* @brief Limited Iteration over another Iterator
|
|
* @author Marcus Boerger
|
|
* @version 1.1
|
|
* @since PHP 5.0
|
|
*
|
|
* A class that starts iteration at a certain offset and only iterates over
|
|
* a specified amount of elements.
|
|
*
|
|
* This class uses SeekableIterator::seek() if available and rewind() plus
|
|
* a skip loop otehrwise.
|
|
*/
|
|
class LimitIterator implements OuterIterator
|
|
{
|
|
private $it;
|
|
private $offset;
|
|
private $count;
|
|
private $pos;
|
|
|
|
/** Construct
|
|
*
|
|
* @param it Iterator to limit
|
|
* @param offset Offset to first element
|
|
* @param count Maximum number of elements to show or -1 for all
|
|
*/
|
|
function __construct(Iterator $it, $offset = 0, $count = -1)
|
|
{
|
|
if ($offset < 0) {
|
|
throw new exception('Parameter offset must be > 0');
|
|
}
|
|
if ($count < 0 && $count != -1) {
|
|
throw new exception('Parameter count must either be -1 or a value greater than or equal to 0');
|
|
}
|
|
$this->it = $it;
|
|
$this->offset = $offset;
|
|
$this->count = $count;
|
|
$this->pos = 0;
|
|
}
|
|
|
|
/** Seek to specified position
|
|
* @param position offset to seek to (relative to beginning not offset
|
|
* specified in constructor).
|
|
* @throw exception when position is invalid
|
|
*/
|
|
function seek($position) {
|
|
if ($position < $this->offset) {
|
|
throw new exception('Cannot seek to '.$position.' which is below offset '.$this->offset);
|
|
}
|
|
if ($position > $this->offset + $this->count && $this->count != -1) {
|
|
throw new exception('Cannot seek to '.$position.' which is behind offset '.$this->offset.' plus count '.$this->count);
|
|
}
|
|
if ($this->it instanceof SeekableIterator) {
|
|
$this->it->seek($position);
|
|
$this->pos = $position;
|
|
} else {
|
|
while($this->pos < $position && $this->it->valid()) {
|
|
$this->next();
|
|
}
|
|
}
|
|
}
|
|
|
|
/** Rewind to offset specified in constructor
|
|
*/
|
|
function rewind()
|
|
{
|
|
$this->it->rewind();
|
|
$this->pos = 0;
|
|
$this->seek($this->offset);
|
|
}
|
|
|
|
/** @return whether iterator is valid
|
|
*/
|
|
function valid() {
|
|
return ($this->count == -1 || $this->pos < $this->offset + $this->count)
|
|
&& $this->it->valid();
|
|
}
|
|
|
|
/** @return current key
|
|
*/
|
|
function key() {
|
|
return $this->it->key();
|
|
}
|
|
|
|
/** @return current element
|
|
*/
|
|
function current() {
|
|
return $this->it->current();
|
|
}
|
|
|
|
/** Forward to nect element
|
|
*/
|
|
function next() {
|
|
$this->it->next();
|
|
$this->pos++;
|
|
}
|
|
|
|
/** @return current position relative to zero (not to offset specified in
|
|
* constructor).
|
|
*/
|
|
function getPosition() {
|
|
return $this->pos;
|
|
}
|
|
|
|
/**
|
|
* @return The inner iterator
|
|
*/
|
|
function getInnerIterator()
|
|
{
|
|
return $this->it;
|
|
}
|
|
|
|
/** Aggregate the inner iterator
|
|
*
|
|
* @param func Name of method to invoke
|
|
* @param params Array of parameters to pass to method
|
|
*/
|
|
function __call($func, $params)
|
|
{
|
|
return call_user_func_array(array($this->it, $func), $params);
|
|
}
|
|
}
|
|
|
|
?>
|